The present invention relates to a height-adjustable guide fitting for a seat belt of a motor vehicle with a rail member connected to the motor vehicle that provides a guide groove with parallel stays in which guide groove a slide is longitudinally displaceable. A locking member biased by a spring is pivotably supported on the slide and is pivotable between a lock position and a release position. The rail member is provided with catch openings spaced at a distance from one another. The locking member has a locking projection for engaging in the locked position one of the catch openings to thereby block the locking member relative to the rail member under the action of the spring. The guide fitting further comprises a device for releasing the locking member. The locking member further has a lock lever pivotable between a position within the contour of the locking member and an outwardly pivoted engaging position for engaging one of the catch openings.
A guide fitting of the aforementioned kind is disclosed in U.S. Pat. No. 4,989,900. When such a height-adjustable guide fitting is a component of a seat belt system with a tightening device, it must be taken into consideration that in all intermediate positions of the guide fitting within the rail member, in which positions no locking of the guide fitting with respect to the rail member is provided, upon activation of the tightening device a locking of the guide fitting in the nearest available catch opening of the rail member is ensured. As a solution to this problem it is suggested in the U.S. Pat. No. 4,989,900 to provide the height-adjustable guide fitting with an additional lock lever attached to the locking member. This lock lever is pivotable between a position within the contour of the locking member and an outwardly pivoted engaging position for engaging one of the catch openings of the rail member. The position in which the lock lever is located within the contour of the locking member allows the guide fitting to freely slide within the rail member. When the lock lever is pivoted outwardly for engaging one of the catch openings of the rail member, a downward movement of the guide fitting exerts torque onto the locking member which results in a pivoting of the locking member into the nearest available catch opening of the rail member.
For activating the lock lever it is suggested in U.S. Pat. No. 4,989,900 that the lock lever, on the one hand, is activated by the acceleration forces resulting from tightening the seat belt, and, on the other hand, that a linkage of the lock lever with the release device for releasing the blockage of the guide fitting is provided so that for displacing the guide fitting upon actuation of the release device the lock lever is also pivoted inwardly into the position within the contour of the locking member.
These suggestions of the prior art have the disadvantage that a control of the lock lever via the aforementioned acceleration forces is not reliably ensured. With respect to a forced coupling with the actuating device, this solution does not provide for the option of upwardly displacing the guide fitting without actuation of the acuating device provided the catch openings are correspondingly designed such that the locking member can slide past the catch openings, but upon load in the downward direction is arrested at these catch openings.
It is therefore an object of the present invention to provide a guide fitting of the aforementioned kind with a simple and secure control of the lock lever.